SPOILERS: Johnny Depp Pays Tribute With 'Rum Diary'

Anyone who has closely followed Johnny Depp's career over the past couple of decades probably knows about his admiration for the late writer, Hunter S. Thompson, at least since he portrayed the author's alter ego Raoul Duke in Terry Gilliam's adaptation of Fear and Loathing in Las Vegas in 1998.

Depp, a close friend and occasional collaborator of Thompson until the author's death in 2005, encouraged his older friend to publish The Rum Diary, a manuscript that was sitting in a box in Thompson's home, collecting dust, while the two were working on Fear and Loathing during the late '90s, according to The Huffington Post. Thompson agreed that he would publish the novel, but only if Depp promised to help him bring it to the big screen.

"Johnny is Hunter in many ways. Hunter set out to do something that no one else had done before, and I feel like Johnny does that in many things," Rum Diary costar Amber Heard said. "He's doing exactly what he wants to do, and I think it's wonderful and important to fight to make projects that he feels have artistic integrity."

The movie stars Depp as Paul Kemp, another alter-ego Thompsonesque character, during a trip he takes to San Juan in his early career as a freelance journalist. While there, the increasingly unhinged protagonist (antihero?) opens the door to the island mentality, kicking back and immersing himself in, well, rum-filled life-style. He becomes obsessed with the betrothed of his employer (Thank You for Smoking's Aaron Eckhart), played by Heard, and simultaneously finds himself faced with the hypocrisy and corruption behind capitalist expansionism in the American Commonwealth.

The film has the distinct mark of a Thompson piece, complete with his familar counterculter themes of substance abuse and the travesty of the "American Dream." It also is played with a lot of heart. "There's nothing more delightful than to see an actor play a role that he puts everything into," producer Graham King praised of Depp's performance. "This was something that was so close to his heart. It wasn't a gig. It wasn't a job for him."

It was important to Depp that his late friend was approprately represented in the film, and that everyone felt like his essence was present during production. Every day on set Depp and director / screenplay adapter Bruce Robinson would pour a highball glass of Chivas Regal for Thompson, which they sat on a desk beside a pack of cigarettes, an ashtray, and a chair with Thompson's name on it.

Watch Depp talk about the movie and Thompson here: